diff --git a/core/modules/views/lib/Drupal/views/Plugin/views/join/Subquery.php b/core/modules/views/lib/Drupal/views/Plugin/views/join/Subquery.php
index 1249f94077c06ebe82930f84edb00b1859922396..1971438de075119c96757edf02e5f0e8eb108001 100644
--- a/core/modules/views/lib/Drupal/views/Plugin/views/join/Subquery.php
+++ b/core/modules/views/lib/Drupal/views/Plugin/views/join/Subquery.php
@@ -60,7 +60,6 @@ public function buildJoin($select_query, $table, $view_query) {
       if (is_array($this->extra)) {
         $extras = array();
         foreach ($this->extra as $info) {
-          $extra = '';
           // Figure out the table name. Remember, only use aliases provided
           // if at all possible.
           $join_table = '';